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Two new PTP Hardware Clock features

PATCH In review Richard Cochran 4 participants 9 messages Sep 22, 2012

Subsystems (7)
Networking Network drivers Intel Ethernet Ethernet PHY +3 more subsystems
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Richard Cochran

author maintainer
#0 lore raw

v3 cover Two new PTP Hardware Clock features

This patch series adds two new features to the PHC code.

* ChangeLog
** V3
- Use the correct parent device in the solarflare driver.
- Expand the sysfs documentation of clock_name.
- Also document the clock_name field in the header file.
** V2
- Preserves the clock_name attribute as it was meant to be, instead of making any changes to it.
- Covers the registration API change in the brand new solarflare phc device, which was overlooked in V1.

The first two patches let a user program find out the previously dialed frequency adjustment. This is primarily useful when restarting a PTP service, since without this information, the presumably correct adjustment will bias the new frequency estimation.

The third patch links the phc class device to its parent device within the driver model and sysfs.

The fourth patch adds a bit more documentation of the sysfs clock_name attribute. This should help clarify the naming scheme.

Thanks,
Richard

Richard Cochran (4):
ptp: remember the adjusted frequency
ptp: provide the clock's adjusted frequency
ptp: link the phc device to its parent device
ptp: clarify the clock_name sysfs attribute

 Documentation/ABI/testing/sysfs-ptp          |    6 +++++-
 drivers/net/ethernet/freescale/gianfar_ptp.c |    2 +-
 drivers/net/ethernet/intel/igb/igb_ptp.c     |    3 ++-
 drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c |    3 ++-
 drivers/net/ethernet/sfc/ptp.c               |    3 ++-
 drivers/net/phy/dp83640.c                    |    2 +-
 drivers/ptp/ptp_clock.c                      |   11 +++++++++--
 drivers/ptp/ptp_ixp46x.c                     |    2 +-
 drivers/ptp/ptp_pch.c                        |    2 +-
 drivers/ptp/ptp_private.h                    |    1 +
 include/linux/ptp_clock_kernel.h             |   11 ++++++++---
 11 files changed, 33 insertions(+), 13 deletions(-)
Signature · 1 line
1.7.2.5
author maintainer
#1 lore raw

PATCH v3 1/4 ptp: remember the adjusted frequency

This patch adds a field to the representation of a PTP hardware clock in order to remember the frequency adjustment value dialed by the user.

Adding this field will let us answer queries in the manner of adjtimex in a follow on patch.

Signed-off-by Richard Cochran <[email protected]>
---
 drivers/ptp/ptp_clock.c   |    1 +
 drivers/ptp/ptp_private.h |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)
drivers/ptp/ptp_clock.c +1 -0
index 966875d..67e628e 100644
@@ -147,6 +147,7 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
 	} else if (tx->modes & ADJ_FREQUENCY) {
 
 		err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
+		ptp->dialed_frequency = tx->freq;
 	}
 
 	return err;
drivers/ptp/ptp_private.h +1 -0
index 4d5b508..69d3207 100644
@@ -45,6 +45,7 @@ struct ptp_clock {
 	dev_t devid;
 	int index; /* index into clocks.map */
 	struct pps_device *pps_source;
+	long dialed_frequency; /* remembers the frequency adjustment */
 	struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
 	struct mutex tsevq_mux; /* one process at a time reading the fifo */
 	wait_queue_head_t tsev_wq;
Signature · 1 line
1.7.2.5
author maintainer
#2 lore raw

PATCH v3 2/4 ptp: provide the clock's adjusted frequency

In reply to Richard Cochran

If the timex.mode field indicates a query, then we provide the value of the current frequency adjustment.

Signed-off-by Richard Cochran <[email protected]>
---
 drivers/ptp/ptp_clock.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
drivers/ptp/ptp_clock.c +5 -0
index 67e628e..6f7009a 100644
@@ -148,6 +148,11 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
 
 		err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq));
 		ptp->dialed_frequency = tx->freq;
+
+	} else if (tx->modes == 0) {
+
+		tx->freq = ptp->dialed_frequency;
+		err = 0;
 	}
 
 	return err;
Signature · 1 line
1.7.2.5
author maintainer
#3 lore raw

PATCH v3 3/4 ptp: link the phc device to its parent device

In reply to Richard Cochran

PTP Hardware Clock devices appear as class devices in sysfs. This patch changes the registration API to use the parent device, clarifying the clock's relationship to the underlying device.

Signed-off-by Richard Cochran <[email protected]>
---
 drivers/net/ethernet/freescale/gianfar_ptp.c |    2 +-
 drivers/net/ethernet/intel/igb/igb_ptp.c     |    3 ++-
 drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c |    3 ++-
 drivers/net/ethernet/sfc/ptp.c               |    3 ++-
 drivers/net/phy/dp83640.c                    |    2 +-
 drivers/ptp/ptp_clock.c                      |    5 +++--
 drivers/ptp/ptp_ixp46x.c                     |    2 +-
 drivers/ptp/ptp_pch.c                        |    2 +-
 include/linux/ptp_clock_kernel.h             |    7 +++++--
 9 files changed, 18 insertions(+), 11 deletions(-)
drivers/net/ethernet/freescale/gianfar_ptp.c +1 -1
index c08e5d4..18762a3 100644
@@ -510,7 +510,7 @@ static int gianfar_ptp_probe(struct platform_device *dev)
 
 	spin_unlock_irqrestore(&etsects->lock, flags);
 
-	etsects->clock = ptp_clock_register(&etsects->caps);
+	etsects->clock = ptp_clock_register(&etsects->caps, &dev->dev);
 	if (IS_ERR(etsects->clock)) {
 		err = PTR_ERR(etsects->clock);
 		goto no_clock;
drivers/net/ethernet/intel/igb/igb_ptp.c +2 -1
index e13ba1d..ee21445 100644
@@ -752,7 +752,8 @@ void igb_ptp_init(struct igb_adapter *adapter)
 		wr32(E1000_IMS, E1000_IMS_TS);
 	}
 
-	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps);
+	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
+						&adapter->pdev->dev);
 	if (IS_ERR(adapter->ptp_clock)) {
 		adapter->ptp_clock = NULL;
 		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c +2 -1
index 3456d56..39881cb 100644
@@ -960,7 +960,8 @@ void ixgbe_ptp_init(struct ixgbe_adapter *adapter)
 	/* (Re)start the overflow check */
 	adapter->flags2 |= IXGBE_FLAG2_OVERFLOW_CHECK_ENABLED;
 
-	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps);
+	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_caps,
+						&adapter->pdev->dev);
 	if (IS_ERR(adapter->ptp_clock)) {
 		adapter->ptp_clock = NULL;
 		e_dev_err("ptp_clock_register failed\n");
drivers/net/ethernet/sfc/ptp.c +2 -1
index 2b07a4e..5b3dd02 100644
@@ -931,7 +931,8 @@ static int efx_ptp_probe_channel(struct efx_channel *channel)
 	ptp->phc_clock_info.settime = efx_phc_settime;
 	ptp->phc_clock_info.enable = efx_phc_enable;
 
-	ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info);
+	ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info,
+					    &efx->pci_dev->dev);
 	if (!ptp->phc_clock)
 		goto fail3;
drivers/net/phy/dp83640.c +1 -1
index b0da022..24e05c4 100644
@@ -980,7 +980,7 @@ static int dp83640_probe(struct phy_device *phydev)
 
 	if (choose_this_phy(clock, phydev)) {
 		clock->chosen = dp83640;
-		clock->ptp_clock = ptp_clock_register(&clock->caps);
+		clock->ptp_clock = ptp_clock_register(&clock->caps, &phydev->dev);
 		if (IS_ERR(clock->ptp_clock)) {
 			err = PTR_ERR(clock->ptp_clock);
 			goto no_register;
drivers/ptp/ptp_clock.c +3 -2
index 6f7009a..b15a376 100644
@@ -186,7 +186,8 @@ static void delete_ptp_clock(struct posix_clock *pc)
 
 /* public interface */
 
-struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info)
+struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
+				     struct device *parent)
 {
 	struct ptp_clock *ptp;
 	int err = 0, index, major = MAJOR(ptp_devt);

@@ -219,7 +220,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info)
 	init_waitqueue_head(&ptp->tsev_wq);
 
 	/* Create a new device in our class. */
-	ptp->dev = device_create(ptp_class, NULL, ptp->devid, ptp,
+	ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
 				 "ptp%d", ptp->index);
 	if (IS_ERR(ptp->dev))
 		goto no_device;
drivers/ptp/ptp_ixp46x.c +1 -1
index e03c406..d49b851 100644
@@ -298,7 +298,7 @@ static int __init ptp_ixp_init(void)
 
 	ixp_clock.caps = ptp_ixp_caps;
 
-	ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps);
+	ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps, NULL);
 
 	if (IS_ERR(ixp_clock.ptp_clock))
 		return PTR_ERR(ixp_clock.ptp_clock);
drivers/ptp/ptp_pch.c +1 -1
index 3a9c17e..e624e4d 100644
@@ -627,7 +627,7 @@ pch_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	}
 
 	chip->caps = ptp_pch_caps;
-	chip->ptp_clock = ptp_clock_register(&chip->caps);
+	chip->ptp_clock = ptp_clock_register(&chip->caps, &pdev->dev);
 
 	if (IS_ERR(chip->ptp_clock))
 		return PTR_ERR(chip->ptp_clock);
include/linux/ptp_clock_kernel.h +5 -2
index a644b29..56c71b2 100644
@@ -21,6 +21,7 @@
 #ifndef _PTP_CLOCK_KERNEL_H_
 #define _PTP_CLOCK_KERNEL_H_
 
+#include <linux/device.h>
 #include <linux/pps_kernel.h>
 #include <linux/ptp_clock.h>
 

@@ -93,10 +94,12 @@ struct ptp_clock;
 /**
  * ptp_clock_register() - register a PTP hardware clock driver
  *
- * @info:  Structure describing the new clock.
+ * @info:   Structure describing the new clock.
+ * @parent: Pointer to the parent device of the new clock.
  */
 
-extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info);
+extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
+					    struct device *parent);
 
 /**
  * ptp_clock_unregister() - unregister a PTP hardware clock driver
Signature · 1 line
1.7.2.5
author maintainer
#6 lore raw

PATCH v3 4/4 ptp: clarify the clock_name sysfs attribute

In reply to Richard Cochran

There has been some confusion among PHC driver authors about the intended purpose of the clock_name attribute. This patch expands the documation in order to clarify how the clock_name field should be understood.

Signed-off-by Richard Cochran <[email protected]>
---
 Documentation/ABI/testing/sysfs-ptp |    6 +++++-
 include/linux/ptp_clock_kernel.h    |    4 +++-
 2 files changed, 8 insertions(+), 2 deletions(-)
Documentation/ABI/testing/sysfs-ptp +5 -1
index d40d2b5..05aeedf 100644
@@ -19,7 +19,11 @@ Date:		September 2010
 Contact:	Richard Cochran <[email protected]>
 Description:
 		This file contains the name of the PTP hardware clock
-		as a human readable string.
+		as a human readable string. The purpose of this
+		attribute is to provide the user with a "friendly
+		name" and to help distinguish PHY based devices from
+		MAC based ones. The string does not necessarily have
+		to be any kind of unique id.
 
 What:		/sys/class/ptp/ptpN/max_adjustment
 Date:		September 2010
include/linux/ptp_clock_kernel.h +3 -1
index 56c71b2..f2dc6d8 100644
@@ -42,7 +42,9 @@ struct ptp_clock_request {
  * struct ptp_clock_info - decribes a PTP hardware clock
  *
  * @owner:     The clock driver should set to THIS_MODULE.
- * @name:      A short name to identify the clock.
+ * @name:      A short "friendly name" to identify the clock and to
+ *             help distinguish PHY based devices from MAC based ones.
+ *             The string is not meant to be a unique id.
  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
  * @n_alarm:   The number of programmable alarms.
  * @n_ext_ts:  The number of external time stamp channels.
Signature · 1 line
1.7.2.5
Acked-by on v3 3/4
#4 lore raw

Re: [PATCH V3 net-next 3/4] ptp: link the phc device to its parent device

In reply to Richard Cochran
Quoted 5 lines · Richard Cochran

PTP Hardware Clock devices appear as class devices in sysfs. This patch changes the registration API to use the parent device, clarifying the clock's relationship to the underlying device.

Signed-off-by Richard Cochran <[email protected]>

[...]

Acked-by Ben Hutchings <[email protected]>
Signature · 3 lines
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
#7 lore raw

Re: [PATCH V3 net-next 4/4] ptp: clarify the clock_name sysfs attribute

In reply to Richard Cochran
Quoted 6 lines · Richard Cochran

There has been some confusion among PHC driver authors about the intended purpose of the clock_name attribute. This patch expands the documation in order to clarify how the clock_name field should be understood.

Signed-off-by Richard Cochran <[email protected]>

[...]

Looks good, thanks.

Ben.

Signature · 3 lines
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
maintainer
#8 lore raw
In reply to Richard Cochran

From: Richard Cochran <[email protected]>
Date: Sat, 22 Sep 2012 19:02:00 +0200

Quoted 18 lines

This patch series adds two new features to the PHC code.

* ChangeLog
** V3
- Use the correct parent device in the solarflare driver.
- Expand the sysfs documentation of clock_name.
- Also document the clock_name field in the header file.
** V2
- Preserves the clock_name attribute as it was meant to be, instead of making any changes to it.
- Covers the registration API change in the brand new solarflare phc device, which was overlooked in V1.

The first two patches let a user program find out the previously dialed frequency adjustment. This is primarily useful when restarting a PTP service, since without this information, the presumably correct adjustment will bias the new frequency estimation.

Quoted 5 lines

The third patch links the phc class device to its parent device within the driver model and sysfs.

The fourth patch adds a bit more documentation of the sysfs clock_name attribute. This should help clarify the naming scheme.

All applied, with a minor coding style correction made to patch #2

Thanks.